Bridge apparatus and method for semiconductor die transfer

Abstract

An apparatus for transferring a semiconductor die (“die”) from the first substrate to the second substrate. The apparatus includes a stage configured to hold a product substrate. A bridge holds a transfer mechanism assembly and a die substrate holder configured to hold the first substrate. A controller is configured to cause the bridge and the transfer mechanism assembly and the die substrate holder to move to align the transfer mechanism assembly with the die on the first substrate with a transfer position on the second substrate where the die is to be transferred.

What is claimed is: 
     
         1 . An apparatus for transferring a semiconductor die (“die”) from a first substrate to a second substrate, the apparatus comprising:
 a first rail extending along a first direction; 
 a second rail extending along the first direction; 
 a bridge structure movably mounted to the first rail and the second rail so as to be movable along the first direction, the bridge structure including a track extending along a second direction that is substantially perpendicular to the first direction; 
 a transfer mechanism assembly including a needle, the transfer mechanism assembly being movably mounted to the track of the bridge structure to move along the second direction; 
 a die substrate holder configured to secure the first substrate, the die substrate holder being movably mounted to the track of the bridge structure to move along the second direction; and 
 a controller configured to:
 control movements of the bridge structure, the transfer mechanism assembly, and the die substrate holder to align the die on the first substrate with the needle of the transfer mechanism assembly with a transfer position on the second substrate where the die is to be transferred, and 
 actuate the needle to push the die into the transfer position on the second substrate. 
 
 
     
     
         2 . The apparatus of  claim 1 , further comprising a movable stage to support the second substrate, the movable stage configured to move the second substrate along at least one of the first direction or the second direction,
 wherein the movable stage is disposed between the first rail and the second rail, and   wherein the controller is configured to control movement of the movable stage.   
     
     
         3 . The apparatus of  claim 2 , wherein the controller is further configured to determine a point of alignment coinciding with the transfer position on the second substrate, the point of alignment to be determined based at least in part on one or more of: (i) a predicted time to transfer the die on the second substrate; or (ii) a predicted placement accuracy of the die on the second substrate. 
     
     
         4 . The apparatus of  claim 1 , further comprising an optical sensor positioned to sense a location of the die on the first substrate with respect to the transfer position on the second substrate. 
     
     
         5 . The apparatus of  claim 1 , further comprising:
 a first motor to move the bridge structure along the first rail and the second rail;   a second motor to move the transfer mechanism assembly along the track of the bridge structure; and   a third motor to move the die substrate holder along the track of the bridge structure,   wherein the controller is communicatively coupled to the first motor to move the bridge structure in the first direction, the second motor to move the transfer mechanism assembly in the second direction, and the third motor to move the die substrate in the second direction, to align the die on the first substrate with the needle of the transfer mechanism assembly with the transfer position on the second substrate.   
     
     
         6 . The apparatus of  claim 1 , further comprising a first sensor to provide the controller an indication of where the transfer mechanism assembly is located along the track of the bridge structure. 
     
     
         7 . The apparatus of  claim 1 , wherein the transfer position is a first transfer position, and,
 wherein the apparatus further comprises:
 a second transfer mechanism assembly including a needle and being movably mounted on the track of the bridge structure; and 
 a second die substrate holder configured to secure a third substrate having at least a second die thereon, the second die substrate holder being movably mounted on the track of the bridge structure, and 
   wherein the controller is further configured to:
 control movements of the second transfer mechanism assembly in the second direction and the second die substrate holder in the second direction to align a second die on the third substrate and the needle of the second transfer mechanism assembly with a second transfer position on the second substrate where the second die is to be transferred, and actuate the needle of the second transfer mechanism to push the second die into the second transfer position on the second substrate. 
   
     
     
         8 . The apparatus of  claim 1 , further comprising a first sensor to provide the controller an indication of where the die substrate holder is located along the track of the bridge structure. 
     
     
         9 . A method for transferring a die from a first substrate to a second substrate comprising:
 moving a bridge along a set of parallel rails;   moving a transfer mechanism assembly along a first track of the bridge;   moving a die substrate holder along a second track of the bridge, the die substrate holder holding the first substrate having the die thereon, aligning a pin of the transfer mechanism assembly with the die on the first substrate in a transfer position on the second substrate; and   actuating the pin to push the die into the transfer position on the second substrate.   
     
     
         10 . The method of  claim 9 , wherein the die is a first die, and
 wherein the method further comprises:
 moving a second transfer mechanism assembly along the first track of the bridge; 
 moving a second die substrate holder, securing a third substrate having at least a second die thereon, along the second track of the bridge, 
 aligning a pin of the second transfer mechanism assembly with the second die on the third substrate and a second transfer position on the second substrate; and 
 actuating the pin of the second transfer mechanism to push the second die into the second transfer position on the second substrate. 
   
     
     
         11 . The method of  claim 9 , wherein aligning the pin of the transfer mechanism assembly with the die on the first substrate in the transfer position on the second substrate comprises actuating the die transfer substrate along at least one of the first direction or the second direction independent of movement of the bridge. 
     
     
         12 . The method of  claim 9 , further comprising moving a movable stage on which the second substrate is disposed such that the position on the second substrate is moved to an alignment point based at least in part on optimizing one or more alignment parameters. 
     
     
         13 . The method of  claim 9 , further comprising determining, based at least in part on an optical sensor signal, a location of the die on the first substrate with respect to the transfer position on the second substrate,
 wherein aligning the pin of the transfer mechanism assembly with the die on the first substrate is based at least in part on the location.   
     
     
         14 . The method of  claim 9 , further comprising receiving a sensor signal indicative of a position of the transfer assembly along the first track of the bridge,
 wherein moving the transfer mechanism assembly along the first track of the bridge is based at least in part on the sensor signal.   
     
     
         15 . An apparatus for transferring a semiconductor die (“die”) from a first substrate to a second substrate, the apparatus comprising:
 a stage configured to hold a product substrate; 
 a bridge coupled to a transfer mechanism assembly and a die substrate holder configured to hold the first substrate; and 
 a controller configured to cause the bridge, the transfer mechanism assembly, and the die substrate holder to move to align the transfer mechanism assembly with the die on the first substrate with a transfer position on the second substrate where the die is to be transferred. 
 
     
     
         16 . The apparatus of  claim 15 , wherein the transfer mechanism assembly includes:
 a needle, and   a needle actuator that moves the needle toward and away from the transfer position on the product substrate responsive to a signal from the controller, and   
       wherein the needle actuator is configured to push the needle against the die to push the die into the transfer position on the second substrate. 
     
     
         17 . The apparatus of  claim 15 , further comprising a sensor in communication with the controller, the sensor configured to indicate a position of the transfer mechanism assembly on the bridge. 
     
     
         18 . The apparatus of  claim 15 , wherein the bridge is configured to move along a pair of parallel rails in a first direction, the transfer mechanism assembly configured to move along a track disposed on the bridge, and the die substrate holder configured to move along the track. 
     
     
         19 . The apparatus of  claim 18 , wherein the die substrate holder is configured to position the first substrate along a first direction and a second direction, the first direction perpendicular to the second direction. 
     
     
         20 . The apparatus of  claim 15 , further comprising an optical sensor positioned to sense a position of the die with respect to the transfer position on the second substrate.